How are you diagnosing it? If you're just throwing random parts at it, you've figured out that's the most expensive and least effective way to find the cause of the problem. You're missing spark, fuel, or compression. Have you done a compression test? Have you checked for diagnostic fault codes? Have you done a cylinder power balance test? What about a tune-up? When you have an engine problem, please list the engine size.

CHECK ENGINE AND TRANNY MOUNTS

I'VE SEEN 'EM TORN/ MISSING NUTS OR BOLTS ALLOWING IT TO BUCK

HAVE A PAL HELP YOU ---PUT IT IN GEAR---W/ THE BRAKES ON---OBSERVE FROM A DISTANCE WHAT MIGHT BE "LOOSE"----MIGHT TRY FORWARD TO REVERSE A FEW TIMES TO SEE WHAT JUMPS

EVEN HOLD THE BRAKE AND GIVE IT A LITTLE GAS

NO GO-EY UNDER WHILE YOUR PAL IS PLAYING WITH THE SHIFTER----DON'T WANNA GET SQUASHED BY THE WHEELS

YOU MAY BE ABLE TO LAY DOWN BESIDE THE THE TRUCK AND LOOK WITH A FLASHLIGHT TO SEE THE TRANNY STUFF

UNDER THE HOOD MAY BE A LOT EZier TO SEE---FROM THE SIDE---NOT THE FRONT!

THE MEDIC